Construction - Learning Pack Unit 3008

Name---------------------------

Learning

Pack

Unit

CC3008

Erect complex structural carcassing components

9.1 Basic roofing terminology

Chapter 9: Structural carcassing

Aims and objectives

At the end of these activity sheets, you should:

be able to name a wide range of roofing components

know the terms used in setting out a roof.

1 Draw lines to join the roofing elements to the correct definition.

verge the triangular part of the end wall of a building that has a pitched roof

eaves where two external sloping surfaces meet

gable where two internal sloping surfaces meet

valley where the roof overhangs at the gable

hip the lowest part of the roof surface where it meets the outside walls

2 List six different rafter types and state what their purpose on the roof is.

1

2

3

4

5

6

3 Correctly label the following diagram.

4 Give a brief definition of each of the following terms:

span

run

apex

pitch line

seat cut

5 Sketch the difference between a single and a double roof.

6 Correctly name the following roof types.

9.2 Trussed roofs


Aims and objectives

At the end of these activity sheets, you should:

define the members and components of a trussed roof

know the setting out for a trussed roof

state the sequence of operations when fitting a trussed roof.

1 This text gives an overview of the manufacture of trussed rafters. Complete the text by

writing the missing words.

Most roofing on ___________ dwellings now comprises ___________-made trussed rafters.

These are made of ________ graded, PAR timber to a wide variety of designs, depending on

requirements. All joints are ______ jointed and held together with _________ plates, face

fixed on either side. These plates are usually made of galvanised ________ and either nailed

or factory ___________. They may also be gang-nailed _________ plates made of 12 mm

resin-bonded ___________.

2 State one of the main advantages of trussed roofs.

____________________________________________________________________

____________________________________________________________________

3 State a disadvantage of standard trusses.

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

4 Describe the steps involved in fixing a gable roof using trussed rafters.

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

____________________________________________________________________

Candidate name: Date:

9.3 Traditional roofing with gable ends


Aims and objectives

At the end of these activity sheets, you should be able to:

define the elements, members and components of a traditional roof with gable ends

know the setting out for a gable-end roof

state the sequence of operations when fitting a gable-end roof.

1 Use geometry to work out the true length of the rafter below.

true length

4.750m

7.450m

2 Put the following steps for marking out a pattern rafter into the correct sequence by marking

them in order, from Step 1 to Step 5.

Mark the true length on the rafter, measuring along the pitch line.

Re-mark the plumb cut to allow for half the thickness of the ridge.

Set the sliding bevel to the plumb cut and mark the angle onto the top of the rafter.

Mark the pitch line 1/3 of the way up the width of the rafter.

Use the sliding bevel to mark out the seat cut, then with a combination square mark out the

birdsmouth at 90 degrees to the seat cut.

3 Complete the following text on fixing rafters by writing in the missing word or words.

Once all the _______ are cut, mark out the wall _____ and fix the rafters. Rafters are

normally placed at ___mm centres, with the first and last rafter __mm away from the _____

wall. The rafters are usually fixed at the foot by ____ nailing into the wall plate and at the

head by nailing through the _____ board.

4 Give a brief description of the two types of finish on a gable end.

1

2

5 Are all the labels on this diagram of finishing a gable end correct? Cross out the incorrect

labels and write the correct ones above them.

6 With the aid of sketches, show two ways to join the fascia to the bargeboard.

7 The following text about fixing bargeboard has four mistakes. Cross out the incorrect words

and write the correct ones above them.

The bargeboard should be fixed using wire nails or lost heads at least 4.5 times the

thickness of the board so that a weak fixing is obtained. If there is to be a joint along the

length of the bargeboard, the joint must be a tenon.

9.4 Traditional roofing with hip ends


Aims and objectives


define the elements, members and components of a traditional roof with hip ends

know the setting out for a hip-end roof

state the sequence of operations when fitting a hip-end roof.

1 Explain with the aid of sketches how the true length of a hip rafter can be worked out.

2 Why is the dihedral angle rarely used these days?

3 Sketch the joint that is used on the wall plate corners.

4 The following text on marking the pitch line on a hip rafter has four mistakes. Cross out the

incorrect answers and write the correct ones above them.

With a hip rafter it is important to forget that the pitch line is marked out differently. It is

marked from the bottom of the rafter and is set at 1/3 the depth of the valley rafter.

5 Explain, with the aid of sketches, how to check the hip measurements.

9.5 Traditional roofing with valleys


Aims and objectives


define the elements, members and components of a traditional roof with valleys

understand how to set out for a valley

state the sequence of operations when fitting a valley.

1 Draw a sketch showing how the true length of a valley rafter can be worked out.

2 Briefly describe a way of creating a valley without using a valley rafter.

9.6 Trimming roof openings


Aims and objectives


describe the elements, members and components used to trim a roof opening

know the setting out procedure for a roof opening

detail the sequence of operations for trimming a roof opening.

1 Complete the following text on trimming roof openings by writing in the missing word

or words.

Roofs often have __________ such as ________ or roof windows. These components create

_____ work, as the roof must have an _______ for them to be fitted. This involves _______

out parts of the ______ and putting in extra _______ to carry the ______ of the roof over the

_______ rafters.

2 With the aid of sketches, show how to trim around a chimney.

3 The following text on trimming a chimney has four mistakes. Cross out the incorrect words

and write the correct ones above them.

When constructing such a floor, the chimney should already be in place, so you should cut

and fit the rest of the roof, leaving out the joists where the chimney is. When you mark out

the wall plate, make sure that the rafters are positioned with a 60mm gap between the

chimney and the rafter. You may also need to put in fewer rafters.

4 Give a brief description of what is involved when fitting a roof window into an existing roof.

5 List three different types of dormer window.

1

2

3

9.7 Eaves details


Aims and objectives


define the elements, members and components of eaves details

give details of the sequence of operations when completing eaves details

1 Complete the following text on eaves details by writing in the missing words.

The _____ are how the lower ____ of the roof is finished where it meets the wall, and

incorporates ______ and ______. The fascia is the vertical board fixed to the ends of the

rafters. It is used to _____ the eaves and allow fixing for _________ pipes. The ______ is the

__________ board fixed to the bottom of the rafters and the wall. It is used to _____ the roof

space to prevent _____ or _______ from nesting there, and usually incorporates

___________ to help prevent ___.

2 Sketch three different ways of finishing a roof at the eaves.

9.8 Ready reckoner


Aims and objectives


understand and read a ready reckoner

use a ready reckoner to set out a roof.

1 Explain what a ready reckoner is and what it is used for.

9.9 Flat roofs


Aims and objectives


name the members and components of a flat roof

know how to set out for a flat roof

state the sequence of operations when fitting a flat roof

detail the operations involved when weatherproofing a flat roof.

1 Complete the following text on flat roofing by writing in the missing word or words.

A flat roof has a ____ to allow _________ to run off, preventing puddles _______ as they can

put extra ______ on the roof and cause _____. Flat roofs will eventually ____, so most are

guaranteed for only __ years (every __ years or so the roof will have to be ________ back

and re-covered). Today __________ flat roofs that last much longer are available, so some

companies will give a 25-year guarantee on their roof. Installing a __________ roof is a job

for __________ roofers.

2. With the aid of sketches, show two different ways that a fall can be achieved on a flat roof.

3 Give a brief description of the following terms relating to flat roofs:

header

camber

abutment

4 List five different types of decking used on a flat roof.

1

2

3

4

5

5 Describe briefly what is involved in weatherproofing a flat roof.

6 Correctly label the following drawing.

7. Why are stones or chippings placed on a flat roof?

9.10 Ground and upper floors


Aims and objectives


name the materials and components required to fit suspended timber floors

state the sequence of operations when fitting suspended timber floors.

1 Show the correct method of working out the depth of a joist if the span is 3 metres.

2 Give a brief description of the following joists, saying what their purpose is.

Bridging

Trimmed

Trimming

Trimmer

3 Sketch a joist hanger.

4 Correctly label the following drawing of flooring.

5 There are seven steps involved in fitting floor joists. What order do they go in? Write the

correct number next to each step to put them in sequence.

Fit folding wedges to keep the end joists parallel to the wall. Overtightening is to be avoided

in case the wall is strained.

Cut joists to length and seal the ends with preservative. Mark out the wall plate with the

required centres, pace the joists out and fix temporary battens near each end to hold the

joists in position. Ends should be kept away from walls by approximately 12mm. It is

important to ensure that the camber is turned upwards.

Bed and level the wall plate onto the sleeper wall with the DPC under it.

Fix the first joist parallel to the wall with a gap of 50mm. Fix trimming and trimmer joists next

to maintain the accuracy of the opening.

Fit restraining straps and, if the joists span more than 3.5m, fit strutting and bridging,

described in more detail next.

Check that the joists are level with a straight edge or line and, if necessary, pack with off-cuts

of DPC.

Fix subsequent joists at required spacing as far as the opposite wall. Spacing will depend on

the size of joist and/or floor covering, but usually 400mm to 600mm centres are used.

6 Describe the steps involved in fitting herringbone strutting.

7 Why is it best to leave a 10-12 mm gap between the floor covering and the wall?

Documents

Construction - Learning Pack Unit 3008